1. Field of the Invention
The present invention relates to overlay of a plurality of images.
2. Description of the Related Art
Certain projectors and other such image display devices are capable of simultaneously displaying image signals from a number of different types of image providing devices. Such devices are capable of simultaneously displaying, for example, images played back by a video tape recorder or images taken with a video camera, superimposed over a graphic image generated by a personal computer. The superimposition of other images (“superimposed images” hereinafter) over a single image (“reference image” hereinafter) is termed “overlay.” Hereinafter, images displayed in overlay mode are termed “overlay images.”
Conventional image display devices include devices that arbitrarily select an order of superimposition of a plurality of superimposed images (“superimposition order” hereinafter), but none of the existing devices is able to arbitrarily select the reference image as well.